The corrosion inhibition of mild steel in molar hydrochloric acid solution by: N1-(2-nitrophenyl)ethane-1,2- diamine (M1) and N1-(2-nitrophenyl)propane-1,3-diamine(M2) has been investigated using gravimetric, potentiodynamic polarization (PP) and electrochemical impedance spectroscopy (EIS) measurements. The influences of inhibitor concentration and solution temperature were investigated. The percentage inhibition efficiency, IE% increased for increasing concentrations and achieved for M1 and M2 96.18% and 94.91% respectively for 10-3M at 298K. The associated activation energy of corrosion process and standard free adsorption energies have been determined. These compounds were adsorbed on the mild steel surface according to Langmuir isotherm adsorption model. Some thermodynamic functions of adsorption and dissolution process were calculated and discussed.